Sjogren's syndrome is a chronic autoimmune disease in which the body's immune system reacts against itself, thus inflicting the common symptoms of dry mouth, nose and possible accompanying arthritis. Like most autoimmune diseases, Sjogren's is predominantly found in females and demonstrates a strong genetic association to the HLA class Il genes. We have recently identified a phenotypic and functional defect in Sjogren's lymphocytes in their ability to stably present self peptides in the groove of HLA class I molecules. The defective genes perhaps causing this defect could be Tap-I or Tap-2, two new recently identified genes directly located within the HLA class II region. Tap-1 and Tap-2 are required for correct assembly of class I with associated self peptides. The purpose of this Small Grant Program is to genetically screen Sjogren's DNA samples by DGGE, denaturing gradient gel electrophoresis, to possibly detect polymorphisms causing functional defects in these ATPase transporter genes, Tap-1 and Tap-2.